This study is designed to investigate beliefs and behavior surrounding tobacco smoking within diverse Alameda County, California bars in which smoking has been banned. Building upon pilot research conducted by the research team in San Francisco bars, the proposed study will explicate the range of enforcement practices and patrons', bartenders', and managers' normative understandings of tobacco use, second-hand smoke, and state tobacco control policies. The overall goal of the proposed study is understanding how and why many stand-alone bars are out of compliance with California AB13, the Smoke-Free Workplace act. The proposed research design consists of a three-year ethnographic study using 110 semi-structured interviews with patrons, bar managers, bartenders and AB 13 enforcement specialists, as well as four waves of structured observations to collect both qualitative and quantitative data in a random sample of 120 bars. The sample bars are drawn from geocoded data on alcohol outlets throughout Alameda County, which includes urban low-income ethnic minority communities and affluent white suburbs as well as rural areas. Because the Alameda County Department of Public Health recently found only 53 percent of stand-alone bars to be in compliance with AB13, the final sample of 120 stand-alone bars is expected to include roughly equal numbers of noncompliant bars and compliant bars. Due to entrenched norms related to smoking in these enclosed, often small, spaces, the stand-alone bar is the public setting in which the population of patrons and employees is at greatest risk for exposure to environmental tobacco smoke. This study's findings will produce understandings of the range of bar patron and employee smoking norms and specific rationales for not complying with the ban. It will also analyze varying AB13 enforcement strategies within the county's communities and their relative success in restricting smoking in bars. These findings constitute a necessary precursor for large-scale preventive efforts with relevance to employees and patrons at risk for exposure to environmental tobacco smoke, including in communities of color.